RBAC Regex fails using Azure OAuth Roles

[mriley-mbgp]

Issue submitter TODO list

• I've looked up my issue in FAQ
• I've searched for an already existing issues here
• I've tried running main-labeled docker image and the issue still persists there
• I'm running a supported version of the application which is listed here

Describe the bug (actual behavior)

After upgrading to Kafbat 1.2.0 via Helm Chart 1.4.12, it is expected that we have support for using regex to identify subjects for roles when configuring RBAC permissions. We use Microsoft Entra ID as a generic OAuth2 Provider, with custom-params configured to set the roles-field to roles, which allows us to utilise App Roles within EntraID to assign our users to the subjects Kafbat is configured to read.

Our redacted OAuth configuration is this:

type: OAUTH2
oauth2:
  client:
    azure:
      clientId: <redacted>
      clientSecret: <redacted>
      scope: openid
      client-name: azure
      provider: azure
      issuer-uri: <redacted>
      jwk-set-uri: <redacted>
      user-name-attribute: email
      custom-params:
        type: oauth 
        roles-field: roles 

Our RBAC is configured like this:

rbac:
    roles:
      - name: "readonly-global"
        clusters:
          - dev
        subjects:
          - provider: oauth
            type: role
            value: ".*-ADMIN"
            isRegex: true
        permissions:
          - resource: clusterconfig
            actions: [ "view" ]
          - resource: topic
            value: ".*"
            actions: 
              - VIEW
          - resource: consumer
            value: ".*"
            actions: [ view ]
          - resource: schema
            value: ".*"
            actions: [ view ]
          - resource: connect
            value: ".*"
            actions: [ view ]
          - resource: acl
            actions: [ view ]
      - name: "readdelete-testrole"
        clusters:
          - dev
        subjects:
          - provider: oauth
            type: role
            value: "dev.engsoft.user"
        permissions:
          - resource: topic
            value: mgp.engsoft\..*
            actions: 
            - MESSAGES_READ
            - MESSAGES_DELETE

Within Azure, I have two roles assigned: dev.engsoft.user via a group assignment and KAFBAT-ADMIN via direct assignment. Both groups are present in the token sent to Kafbat, which can be seen in the logs, however, Kafbat does not respect the regex assignment of .*-ADMIN and only assigns roles that exactly match, regardless of the isRegex field value.

Here are logs of this with the above configuration:

2025-03-25 16:30:04,457 TRACE [reactor-http-epoll-9] i.k.u.s.r.e.OauthAuthorityExtractor: Extracting OAuth2 user authorities
2025-03-25 16:30:04,458 DEBUG [reactor-http-epoll-9] i.k.u.s.r.e.OauthAuthorityExtractor: Principal name is: [<redacted email>]
2025-03-25 16:30:04,459 DEBUG [reactor-http-epoll-9] i.k.u.s.r.e.OauthAuthorityExtractor: Matched roles by username: []
2025-03-25 16:30:04,459 TRACE [reactor-http-epoll-9] i.k.u.s.r.e.OauthAuthorityExtractor: The field is either a set or a list, returning as is
2025-03-25 16:30:04,459 DEBUG [reactor-http-epoll-9] i.k.u.s.r.e.OauthAuthorityExtractor: Token's groups: [KAFBAT-ADMIN,dev.engsoft.user]
2025-03-25 16:30:04,459 DEBUG [reactor-http-epoll-9] i.k.u.s.r.e.OauthAuthorityExtractor: Matched group roles: [readdelete-testrole]

Setting the subject to the following shows the permission successfully assigns:

 subjects:
- provider: oauth
  type: role
  value: "KAFBAT-ADMIN"
  isRegex: true

2025-03-25 16:56:18,855 TRACE [reactor-http-epoll-8] i.k.u.s.r.e.OauthAuthorityExtractor: Extracting OAuth2 user authorities
2025-03-25 16:56:18,855 DEBUG [reactor-http-epoll-8] i.k.u.s.r.e.OauthAuthorityExtractor: Principal name is: [<redacted email>]
2025-03-25 16:56:18,856 DEBUG [reactor-http-epoll-8] i.k.u.s.r.e.OauthAuthorityExtractor: Matched roles by username: []
2025-03-25 16:56:18,856 TRACE [reactor-http-epoll-8] i.k.u.s.r.e.OauthAuthorityExtractor: The field is either a set or a list, returning as is
2025-03-25 16:56:18,856 DEBUG [reactor-http-epoll-8] i.k.u.s.r.e.OauthAuthorityExtractor: Token's groups: [KAFBAT-ADMIN,dev.engsoft.user]
2025-03-25 16:56:18,857 DEBUG [reactor-http-epoll-8] i.k.u.s.r.e.OauthAuthorityExtractor: Matched group roles: [readonly-global, readdelete-testrole]

It appears that the configuration of isRegex is ignored entirely. For the record, the regex we use for topic naming permissions within these roles all work as expected, which points directly to the implementation of Subject regex parsing.

Expected behavior

It is expected that for a regex, Kafbat matches any roles that succeed against that regex to the group. The above .*-ADMIN example is taken directly from the documentation - in reality, we want it to match an even simpler regex of .* so we can assign any role a set of global default permissions.

Your installation details

We're running:

• App version v1.2.0 3074abc
• Helm chart version 1.4.12

yamlApplicationConfig:
    kafka:
      internalTopicPrefix: _ui_
      clusters:
        - name: dev
          bootstrapServers: dev-kafka-bootstrap.dev-kafka.svc.cluster.local:9092
          schemaRegistry: http://conf-schema-registry:8081
          readonly: false
          properties:
            security:
              protocol: SASL_PLAINTEXT
            sasl:
              mechanism: PLAIN
              jaas:
                config: org.apache.kafka.common.security.plain.PlainLoginModule required username="<redacted>" password="<redacted>" ;
    auth:
      type: OAUTH2
      oauth2:
        client:
          azure:
            clientId: <redacted>
            clientSecret: <redacted>
            scope: openid
            client-name: azure
            provider: azure
            issuer-uri: <redacted>
            jwk-set-uri: <redacted>
            user-name-attribute: email
            custom-params:
              type: oauth
              roles-field: roles
    logging:
      level:
        root: info # trace,debug, info, warn, error. default: info
        io.kafbat.ui.service.rbac: TRACE
    rbac:
      roles:
        - name: "readonly-global"
          clusters:
            - dev
          subjects:
            - provider: oauth
              type: role
              value: "KAFBAT-ADMIN"
              isRegex: true
          permissions:
            - resource: clusterconfig
              actions: [ "view" ]
            - resource: topic
              value: ".*"
              actions: 
                - VIEW
            - resource: consumer
              value: ".*"
              actions: [ view ]
            - resource: schema
              value: ".*"
              actions: [ view ]
            - resource: connect
              value: ".*"
              actions: [ view ]
            - resource: acl
              actions: [ view ]
        - name: "readdelete-testrole"
          clusters:
            - dev
          subjects:
            - provider: oauth
              type: role
              value: "dev.engsoft.user"
          permissions:
            - resource: topic
              value: mgp.engsoft\..*
              actions: 
              - MESSAGES_READ
              - MESSAGES_DELETE

Steps to reproduce

Deploy Kafbat via chart with the above configuration and correct setup in EntraID and the result is reproducible.

Screenshots

No response

Logs

Additional context

This was discussed in the community Discord. We tried the suggestion of changing isRegex to isIsRegex but this didn't work.

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[rahulrg09]

@mriley-mbgp
I tried using regex instead of isRegex and it worked.

[mriley-mbgp]

@rahulrg09 Thanks for that, this appears to be the case for me as well - it is now working as intended when using regex. I guess this issue now comes down to whether the documentation should be updated to match this behaviour, or understanding why the intended isRegex isn't working.

[Haarolean]

doesn't work due to jackson/lombok shenanigans, will fix soon